refactor: Phase 3 拆分 generate 流水线并补全测试

提取 collect/formatters/themes 等 pipeline 模块，新增 wecom 分条、RSS、delta、Agent 工作流测试。

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_smoke.py

@@ -36,11 +36,12 @@ def test_generate_report_offline(
     monkeypatch,
 ):
     import daily.generate as generate
+    import daily.pipeline.collect as collect
 
-    monkeypatch.setattr(generate, "load_feed", lambda force=False: skills_feed)
-    monkeypatch.setattr(generate, "fetch_github_trending", lambda n: [_sample_github_repo()])
-    monkeypatch.setattr(generate, "fetch_emerging_repos", lambda n, exclude=None: [])
-    monkeypatch.setattr(generate, "fetch_topic_hot_repos", lambda n, exclude=None: ("llm", []))
+    monkeypatch.setattr(collect, "load_feed", lambda force=False: skills_feed)
+    monkeypatch.setattr(collect, "fetch_github_trending", lambda n: [_sample_github_repo()])
+    monkeypatch.setattr(collect, "fetch_emerging_repos", lambda n, exclude=None: [])
+    monkeypatch.setattr(collect, "fetch_topic_hot_repos", lambda n, exclude=None: ("llm", []))
     monkeypatch.setattr(generate, "_now_cst", lambda: fixed_cst)
 
     _, wecom_md, out_md, out_wecom = generate.generate_report()